1. Field of the Invention
The present invention relates to a storage box, and more particularly to a storage box having a fastening mechanism that enables easy and quick opening and re-closing of the storage box.
2. Description of the Prior Art
Various types of packaging products, such as food wraps, storage boxes, storage bags, etc., that are made of materials suitable for using with microwaves have been developed for use in a wide range of fields. Among these packaging products, the storage boxes for containing instant foods are particularly welcome due to their ability of keeping food fresh for a prolonged time without leaving any bad plastic smell. These storage boxes also have the advantages of easy to clean, resistant to high and low temperatures, not easily corroded by acids and alkalis, and particularly, useable with microwaves.
FIG. 1 shows a conventional storage box A1 widely used by instant food stores to hold hamburgers, fried chickens, etc. As shown, the conventional storage box A1 typically includes an upper cover A2 and a lower cover A3 integrally connected at a rear edge of the box. In early stage, marginal belts A21, A31 of the upper and the lower covers, respectively, are directly stapled together to close the upper cover A2 to the lower cover A3. This manner of closing the storage box A1 is bothersome because a stapler is needed to close the storage box A1 and the staples must be removed before the storage box A1 could be opened. And, once the storage box A1 is opened, it could not be closed again without a stapler.
To solve the above-mentioned problems, a fastening mechanism has been developed for the conventional storage box A1. As shown in FIG. 1, the fastening mechanism includes two fastening portions A4 correspondingly provided at proper positions on the marginal belts A21, A31 of the upper and the lower covers A2, A3, respectively. Please refer to FIG. 2. The two fastening portions A4 are integral parts of the marginal belts A21, A31 of the upper and the lower covers A2, A3, respectively, and are so shaped that the lower fastening portion A4 is tightly fitted into the upper fastening portion A4 when the upper cover A2 is fully closed onto the lower cover A3. That is, the two fastening portions A4 are tightly joined together in a mortise-and-tongue relation. This type of mortise-and-tongue joint has the following disadvantages:
1. For the two fastening portions A4 to provide a good fastening effect, the upper fastening portion A4 provides a mortise that is slightly smaller than a tongue provided by the lower fastening portion A4, so that the mortise and the tongue could firmly engage with each other. Thus, there is not any fit clearance between the two fastening portions A4. In this tight fit relation, the lower fastening portion A4 tends to become stuck in the upper fastening portion A4. When a force that is applied to separate the two tightly joined fastening portions A4 is too strong, the fastening portions A4 would inevitably become deformed and lose their fastening function, preventing the upper and the lower covers A2, A3 from closing again via the fastening portions A4. In a worse condition, the entire storage box A1 is deformed, broken or careless turned over.
2. Since the upper and the lower marginal belts A21, A31 are designed to completely contact with one another when the upper cover A2 is fully closed onto the lower cover A3, and there is a contact stress produced at the time the storage box A1 is closed, a user encounters increased difficulties in separating the upper marginal belt A21 from the lower marginal belt A31. Some users might try to open the storage box A1 by extending fingernails into the tight joint between the upper and the lower marginal belts and unfortunately get injured at the fingers.
It is therefore tried by the inventor to develop a storage box that has a fastening mechanism enabling the storage box to be easily opened and re-closed without becoming damaged.
A primary object of the present invention is to provide a storage box that eliminates the problem of tightly contacted upper and lower marginal belts and injured fingernails attempting to separating such marginal belts from one another.
Another object of the present invention is to provide a storage box that omits the conventional tight-fit fastening portions to avoid the problem of deformed storage box due to an overlarge force applied to open the fastening portions.
A further object of the present invention is to provide a storage box having retreated portions for a user to stably hold thereat to close or open the storage box without causing a turned-over box.
A still further object of the present invention is to provide a storage box having expanded antislip areas, at where a user may apply forces to instantly and stably close or open the storage box.
To achieve the above and other objects, the storage box of the present invention mainly includes an upper cover integrally connected at a rear edge to a lower cover. The upper and the lower covers are provided along their peripheral edges with a recess and a flange, respectively, that engage with each other when the upper cover is closed onto the lower cover.
Upper and lower marginal belts surrounding the recess and the flange, respectively, are provided at front corners with coarse areas, on which projections are provided so that a gap always exists between the two marginal belts to facilitate easy opening of the upper cover relative to the lower cover. The coarse areas provide good antislip effect when a user""s fingers contact with them.
The recess and the flange are provided with tongues. The tongue on the recess goes to abut a lower side of the tongue on the flange when the upper cover is fully closed onto the lower cover, and thereby locks the upper cover to the lower cover. The tongues allow a fit clearance between the recess and the flange, so that the upper and the lower covers would not become stuck at the recess and the flange when they are closed to each other.
The upper cover is provided at two front corners with two retreated portions, so that two expanded areas are formed at the two front corners immediately in front of the two retreated portions to provide good places at where the user may conveniently apply forces to close the upper and the lower covers 2, 3 together. Antislip strips are provided on the expanded areas to ensure stable contact of the user""s fingers with the expanded areas to apply the forces. By applying forces at the expanded areas, the tongues on the recess and the flange could be quickly brought into place to lock the two covers together.